The present disclosure relates generally to machines and more particularly to methods and devices for use in fluid treatment of the machines.
Machines such as motors generate heat during operation as a result of both electrical and mechanical losses. Typically, an electric motor must be cooled to facilitate the desired and efficient operation of the motor. An excessively high motor temperature may result in motor bearing failure or damage to the stator or to the rotor.
Designing a motor involves many considerations. For example, rotor temperature is a limiting factor in motor design as the rotor can generate a proportionally high amount heat for the motor. At least some known electric motors include an enclosure including a frame and endshields. The most common enclosures are “open” or totally enclosed. In an “open” enclosure, ambient air circulates within the enclosure, and heat is removed by convection between the air and heat generating motor components within the enclosure. The heated air is exhausted from the enclosure. Because such enclosures are open, the locations in which such motors may be used are generally limited.
In contrast, totally enclosed type enclosures typically are often used in applications in which airborne contaminants, e.g., dirt, oil, or mist, must be prevented from entering within the enclosure. Both convection and conduction type cooling occurs within the enclosure, and some form of convection cooling occurs along the external surfaces of the enclosure. For example, forced convection cooling can be provided by a fan directly mounted to the motor shaft external the enclosure. Efficiently cooling the drive end side of the motor and components such as the rotor, however, enhances operation of the motor. However, an externally, shaft mounted fan provides limited heat dissipation with respect to the drive end side of the motor. Consequently, components within the enclosure, such as the drive end bearings may still overheat due to inefficient cooling. Additionally, shaft mounted fans also provide limited heat dissipation with respect to the rotor.